Encounter hundreds of species of bacteria that exist nowhere else on the planet outside of a termite's gut. These microbes enable their termite host to digest the wood it infamously devours. The termite and these microbes share what is called an obligate endo-symbiotic relationship. That means neither could survive without the other's help, and one species lives inside the other.
It should be noted that only 10% of the 2500 species of termite on the planet cause damage to human habitation. Overall, termites are absolutely essential to recycling dead plant material. Without them, and by extension these invisible microbes, the surface of the Earth would be buried under miles of rotting plant material.